Quick-acting reducing valve



United States Patent O QUICK-ACTIN G REDUCING VALVE Application June 25,1953, Serial No. 364,095

1 Claim. (Cl. 137-488) This invention relates to a valve particularlydesigned for reducing and controlling heavy gas pressures 1n combustionapparatus.

It is the general object of the invention to provide a reducing valvewhich will provide and maintain a heavy uniform operating pressure. Afurther object is to provide a reducing valve having special provisionfor qulck response to a drop in pressure in the controlled apparatus.

The invention further relates to arrangements and combinations of partswhich will be hereinafter described and more particularly set forth inthe appended claim.

\A preferred form of the invention is shown in the drawing which is asectional side elevation of the improved reducing valve.

`Referring to the drawing, the valve V comprises a body having an inletpipe 11 `and an outlet pipe 12. The inlet pipe 11 is to be connected toany suitable supply of high pressure gas, and the pipe 12 may beconnected to a tank T or to any other apparatus in which a uniform butreduced gas pressure is to be maintained.

The pipe 1'1 is connected into a lower chamber 15 in the body 10, andthe pipe 12 is connected into an upper chamber 16. The chambers 15 and16 are separated by 4a partition 18 having a reduced connecting openingor port 19.

A valve member is positioned below the port 19, and a spring 21 tends toraise the valve member 20 to closing position. The lower end of thespring 21 is seated in a recess 22 in a cap or nut 23 which also closesthe lower end of the chamber 15.

A control unit U is mounted above the valve V and comprises a maincasing 30 having a downward projection 31 adapted to be threaded intothe upper end of the body 10. A bellows B is housed in the casing 30,and the lower or free end of the bellows is rmly secured to a movablebottom plate 32.

The upper end of the bellows B is secured in a ring 34 which is clampedbetween the upper surface of the casing 30 and the under side surface ofa casing head 35, these parts being firmly held together by screws 36.

A casing member V2 is mounted on the bottom plate 32 and encloses avalvedopening plunger 40 pressed upward by a coil spring 41, so that itnormally closes a port 42 in the upper end of the casing member. Thelower end of the plunger 40 engages a second plunger 4S slidable in anaxial passage in the downward projection 31 of the main casing 30.

At its lower end, the plunger 45 is reduced, as indicated a't 46, andpasses loosely through the port 19 to engage the head of the valvemember 20. When the bottom plate 32 is in its lowest position, asindicated in the drawing, the plungers 40 and 45 are of such length thatthe valve 20 will be forced downward to open the port 19.

Relatively heavy springs S and S2 are provided within the bellows B, andat their lower ends they engage and press downward the bottom plate 32.At their upper ends, they engage a cap 47 loosely mounted at the lowerend of an adjusting screw 48 which is threaded into the upper 2,770,251Patented Nov. 13, 1956 end of the casing head 35. By turning the screw48, the pressure of the springs S and S2 may be adjusted.

The apparatus thus far described operates as follows:

The valve V is normally open. When pressure is admitted through the pipe11, gas under pressure llows through the port19 to the outlet pipe 12and tank T.

Small holes H are provided in the casing extension 31,

and as pressure rises in the outlet pipe 12 and tank T, increased'pressure is applied through the holes H to the under side of the bottomplate 32. This pressure eventually` overcomes the springs S and `S2 andraises the bottom plate 32 and casing member V2. The valveopeningplunger 40 likewise rises and permits the lower plunger 45 and the valvemember 20 to rise and to thereby decrease the open area of the port 19.In due course, these parts will assume a substantially static position,with the port 19 open just enough to maintain the desired reducedpressure in the tank T or in other apparatus to which the reducing valveV is connected. The exact amount of this reduced pressure may bedetermined by the setting of the adjusting screw 48.

Special provision is made for restoring the desired uniform pressure,when an increase in demand on the tank T or other operated apparatuscauses a drop in the pressure to be uniformly maintained.

iFor this purpose, a by-pass connection 50 extends from the tank T to anauxiliary valve V3, which in turn is connected by a pipe 51 into thecasing head 35 and hence into the interior of the bellows B. The valveV3 comprises a cylinder 60 having a piston 61 mounted on a piston rod 62which is freely slidable axially. An auxiliary pressure tank T2 isconnected with the cylinder 60 by a pipe 64 positioned opposite the pipe51 previously described.

When the tank T is under normal reduced pressure, this normal pressureis applied through the pipe 50 to the right-hand end of the cylinder 60and holds the piston 61 against stop-pins 66, at the same timecompressing a coil spring 67. In this position, the piston 61 closes thepipes 64 and 51.

At this same time, a second piston 70 assumes the position shown in thedrawing and uncovers the upper end of a by-pass connect-ion 72 betweenthe pipe 51 and a vent 73, so that the pressure in the interior of thebellows B is atmospheric and there is no downward gas pressure on thebottom plate 32.

If an `increased demand on the tank T or other apparatus causes a dropin the selected reduced pressure, the pressure in the auxiliary cylinder60 correspondingly drops, so that the spring 67 overcomes the pressurein the cylinder 60 and moves the pistons 61 and 70 to the right. Thepiston 70 thereupon closes the: venting by-pass 72, and the piston 61uncovers the auxiliary pressure pipe 64 and opens the connection thereofthrough the pipe 51 to the interior of the bellows B.

yAdditional pressure is thus exerted on the bottom plate 32, forcing itto move downward against the pressure on the under side of the pl-ateand thus further depressing the valve member 20 and increasing theoperative area of the port 19. An increased llow of gas through theoutlet pipe 12 to the tank T then takes place, and the desired uniformpressure is restored.

As the action of the relatively large bellows B is rather slow, thecasing member V2 and plunger 40 are provided to produce quicker action.As soon as the auxiliary valve V3 has admitted pressure to the controlunit, the increased pressure acts directly on the plunger 40, depressingthe valve plunger and promptly pushing the valve member 20 downwardwithout waiting for the relatively slow downward movement of the bottomplate 32.

`Provision is thus made for maintaining and restoring a deslred uniformpressure in the tank T or other apparatus, and also for inducing quickaction on the event of `a ysudden drop in pressure on the tank T.

The apparatus above described has been found effective and satisfactoryin controlling pressures as high as 800 lb's. per square inch, y Y

Having thus described the invention and the advantages thereof, it willbe understood that the vinver'ition is not to be limited to the detailsherein disclosed, otherwisevthan as set forth inthe claim, but what isclaimed is:

A quick-acting reducing valve for a controlled pressure systemcomprising ya valve body having inlet and discharge connections, .aninterposed port and .a valve member therefor, .a spring to move saidyvalve member inra direction to close said port, a control unitcomprising'an actuating part movable to engagey and shiftsaidvalve-member to open said port, springs to effect such movement ofsaid actuating part, a Vpressure connection between the dischargepassage of said reducing valve and said'control unit, whereby thedischarge pressure balances the spring pressure at a predeterminedregulating position of said valve member, and said control unitincluding a bellows member, means to .admit auxiliary air under pressurefrom an auxiliary air supply to said bellows member to further open saidreducing valve on a drop in pressure in the controlled system, andquick-acting auxiliary means to accelerate the valve-opening action ofsaid actuating part, and said quick-acting auxiliary means comprising amember in said control unit, which member is directly exposed to saidauxiliary air under pressure and which member -acts directly to movesaid actuating part and to thereby quickly open said reducing valve whensaid member is moved by said auxiliary air under pressure and before thebellows member' completes its relatively slow response tol saidauxiliary air pressure..

References Cited in the iile of this patent UNITED STATES PATENTS

